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Re: 92 gmc no idle
Posted to Technical Discussion Forum on 6/19/2008

The MAP-V is indicating low manifold vacuum. If you are 100% sure that the EGR valve isn't leaking (I suspect it is), put a vacuum gauge on it and tell us what you have for manifold vacuum at your "best idle". Should be around 19 or 20in HG.

If vacuum is low... Login to read more.